Herbal Vaporizing Device

ABSTRACT

A device for vaporizing herbal smoking materials such as tobacco has a base with a trench and an electrically-insulating block disposed in the trench. The trench has two sides. A first side contains a U-shaped electrical heating element. A second side is for receiving a battery. Electrical contacts extend between the first side and second side. The electrical contacts are connected to terminal ends of the heating element. In operation, the battery is connected to the electrical contacts, allowing electrical power to flow through the heating element. A window can cover the first side, so that the bowl area is enclosed. A sliding switch can be disposed in the second side to provide pushbutton manual control of electrical power to the heating element.

RELATED APPLICATIONS

The present application claims the benefit of priority from provisionalpatent applications 61/690,145 filed on 06/20/2012 and 61/796,649 filedon Nov. 16, 2012.

FIELD OF THE INVENTION

The present invention relates generally to smoking devices andvaporization devices. More particularly, the present invention relatesto a battery powered vaporizer device with a novel, low-cost and readilymanufacturable design.

BACKGROUND OF THE INVENTION

Tobacco, kinnick kinnick, or other herbs are typically smoked by burningand inhaling the combustion fumes and smoke. In recent years, interesthas grown in the technique of vaporization in which the smoking materialis carefully heated so that the desired flavor and psychoactivecomponents are liberated, and combustion is minimized. Vaporizationprovides many benefits over smoking. When performed properly,vaporization does not produce nearly as much toxic and carcinogeniccombustion products as smoking Also, vaporization is smoother and moreflavorful, and lacks a burned taste that many find disagreeable.Further, vaporization allows more efficient use of smoking materials,since desired flavor and psychoactive compounds are not destroyed bycombustion. There are a number of battery powered, portable vaporizingdevices available today. Many of these devices are expensive ($250 andup), or have short battery life. High cost is driven by complex controlelectronics, high parts count and temperature sensor feedback control.Also, many of these vaporizing devices are difficult to clean or are notuser-repairable.

There is a need for a simple, reliable, and inexpensive battery poweredvaporizing device with a long battery life and that is user-repairable.

Also, many portable electronic vaporizing devices contain large amountsof plastic. These plastic parts can become heated when herbs arevaporized, creating offensive plastic odors or flavors. Many consumersdistrust portable vaporizers that are made of plastic.

Accordingly, there is a need for a portable vaporizing device that doesnot contain plastics, or contains only very small amount of plastic notlocated near where high temperatures are generated. In particular, itwould be desirable to provide a portable, battery powered vaporizer thatis comprised almost exclusively of wood, metals, and glass.

SUMMARY

The present invention includes a vaporizing device having a base with atrench, a U-shaped heating element, an insulator block, and twoelectrical contacts and a cover. The block is disposed in the trench,and divides the trench into a first side and a second side. The firstside is for receiving smoking material; the second side is for receivinga battery (or electrical connector shaped like a battery). The heatingelement is disposed in the first side, and is oriented with the openside of the U-shape facing toward the block. The two electrical contactsextend between the first side and second side, and are electricallyconnected to terminal ends of the heating element. The cover is forcovering the first side, and can be removably attachable to the base,for example with magnets.

The electrical contacts can extend through the body of the block, or canbe located between the block and trench sidewalls. The block can be aseparate part from the base, attached to the base (e.g., with screws orglue for example), or can be monlithic with the base.

The heating element can comprise a strip of metal foil or wire cloth.The heating element can be perforated or corrugated.

A sliding switch can be disposed in the second side, movable toward theblock such that it provides electrical connection between the batteryand one of the electrical contacts.

A battery holder can be present over the second side, for holding abattery (or electrical connector) in the second side.

A battery charge indicator can be electrically connected between theelectrical contacts. The battery charge indicator can indicate a stateof charge of the battery. The battery charge indicator can be disposedin the block, or on the block.

DESCRIPTION OF THE FIGURES

FIG. 1 shows a perspective view of the present vaporizing device, withthe cover window removed for clarity.

FIG. 2 shows the base part in isolation.

FIG. 3 shows a top view of the vaporizing device, with the batteryholder removed for clarity.

FIG. 4 shows the U-shaped heating element and insulator block inisolation (the “heating assembly”)

FIG. 5 is a cross sectional side view illustrating operation of themagnetically-retained window.

FIG. 6 is a cross sectional view illustrating how the battery holderretains the battery.

FIGS. 7A-7C illustrate the operation of the sliding electrical switch.

FIG. 8 shows an embodiment in which the window opens by pivoting orrotating.

FIG. 9 shows an embodiment in which the sliding switch is not present,and power to the heating element is controlled by pressing the battery.

FIG. 10 shows an embodiment in which the battery is oriented at 90degrees.

FIG. 11 shows an embodiment in which the trench has a cylindrical shape,and the heating element partially conforms to this shape.

FIG. 12 shows a top view of the embodiment of FIG. 11.

FIG. 13 shows an embodiment in which the heating element comprises ametal foil (or other flat conductor) that is corrugated and orientedhorizontally.

FIG. 14 shows an embodiment in which electrical contacts extend throughthe block 24.

FIG. 15 shows an embodiment in which the heating element has an extrabend.

FIG. 16 shows an embodiment in which the heating element is in the shapeof a nearly-closed loop.

FIG. 17 shows an embodiment in which the base has a back wall thatsurrounds the battery.

DETAILED DESCRIPTION

The present invention provides a portable electronic vaporizing devicewith numerous features and advantages. The present vaporizing device hasa simple, low-cost construction that can be made almost exclusively ofwood, metals and glass. The present vaporizing device is compatible withhigh-energy density, high-voltage (e.g. 2-4 volt) storage batteries suchas lithium-ion, lithium iron phosphate, or sodium ion batteries.

The present vaporizing device has a base with a trench, and a U-shapedheating element in the trench. The U-shaped heating element is attachedto electrical contacts for connecting to a battery disposed in thetrench. Herbal material to be vaporized is disposed in the trench, incontact with a heating element. An insulator block is also disposed inthe trench, between the battery and the U-shaped heating element. Aswitch can provide simple manual power control. Also, a window can bedisposed over the trench and heating element. The present vaporizer issimple, low-cost and can be made of non-toxic materials trusted by vaporenthusiasts: wood, metals and glass. Also, the relatively long U-shapedheating element is a good electrical resistance match for high-energystorage batteries which tend to have high single cell voltages (i.e. inthe 2-4 volt range).

FIG. 1 shows a perspective view of a vaporizing device according to anembodiment of the present invention. The device has a base 20, a battery22, an insulator block 24 and a U-shaped heating element 26. A batteryholder 28 holds the battery 22 in the base 20 by friction. The batteryholder 28 has a cantilevered tab 29 defined by a cut-out area 31. Thecantilevered tab 29 presses down against the battery 22. The battery isremovable by sliding in direction of arrow 25.

A transparent cover window 30 has an embedded window magnet 32 forattachment to the base 20. The base 20 has a slot 34 that contains abase magnet (not visible) for attachment to the window magnet 32. Theslot 34 is sized to receive the window magnet 32 with minimal friction.

The heating element 26 is wrapped around a bowl area 38, where smokingmaterial is placed. A sliding switch 39 is used for controlling powerflow to the heating element 26. The sliding switch 39 is made ofresilient, springy material with good electrical contact properties,such as phosphor bronze, brass, or copper-plated steel.

FIG. 2 shows the base 20 in isolation. The base 20 has a trench 40. Inthe specific embodiment shown in FIG. 2, the trench 40 has an open end42 and a closed end 44. In other embodiments described below, the trench40 can be open on both ends, or closed on both ends. The closed end 44has a mouthpiece hole 46 that is not visible in FIG. 1. The hole 46 isfluidically connected to the mouthpiece 36. The trench 40 also has rightand left side sidewalls 40RSW 40LSW. The base 20 is preferably made ofan electrically insulating and thermally insulating material, such aswood, high temperature plastics, or ceramic. If wood is used, it shouldbe resistant to charring. A suitable wood with such properties is hardmaple.

The block 24 can be made of the same material as the base 20.

The block 24 can be monolithic with the base, or can be attached to thebase with screws, adhesive or the like. For example, screws can extendthrough the bottom of the trench 40 into the block 24.

FIG. 3 shows a top view of the vaporizing device. For clarity, thebattery holder 28 is not shown. The U-shaped heating element 26 hasterminal ends 26T electrically connected to electrical contacts 50 52.Sliding switch 39 can move in the direction of arrow 54. Compressionspring 56 pushes the sliding spring to the right, so that the switch 39has a momentary-ON pushbutton switching action, as explained in moredetail below.

The trench 40 has a first side 60 and a second side 62, separated by theinsulator block 24. The U-shaped heating element 26 is disposed in thefirst side 60, with an open side of the U-shape oriented towards theblock 24. The battery 22 is insertable in the second side 62.

The electrical contacts 50 52 provide electrical connections between thefirst side 60 and second side 62. The electrical contacts 50 52 extendaround the block 24, i.e. between the block 24 and sidewalls 40LSW 40RSWof the trench 40. In alternative embodiments, described below, theelectrical connections 50 52 extend through the body of the block 24instead of around the block 24. Electrical contacts 50 52 can be made ofa resilient, springy metal with good electrical contact properties, suchas phosphor bronze, brass, or copper-plated steel.

The terminal ends 26T may extend into the space between the block 24 andthe sidewalls 40LSW 40RSW.

In the embodiment of FIG. 3, an inner portion 391 of the switch 39 isangled away from the right sidewall 40RSW. In other words, angle A isgreater than 90 degrees (e.g. about 94-97 degrees). This will cause theinner portion 391 to press against the battery when the battery isdisposed in the second side 62, as described below.

FIG. 4 shows the U-shaped heating element 26 and block 24 in isolation.It can be clearly observed that the electrical contacts are wrappedaround the block 24. The heating element 26 has a vertical height 47that is preferably slightly less than a depth of the first side 60trench. This will result in a slight gap (e.g. 0.005-0.030″) between theheating element and window 30 when the window 30 is attached to the base20. It is preferable (but not absolutely essential) for the heatingelement 26 and window 30 to not be in contact. The heating element 26and contacts 50 52 are mechanically and electrically connected. Forexample, the heating element 26 and contacts 50 52 can be connected bysoldering, electrical-pulse spot welding, or crimping, for example. Theelectrical contacts 50 52 can be held in place by compression betweenthe block 24 and trench sidewalls 40LSW 40RSW. Also, the contacts 50 52can have bumps 57, ridges or other non-planar features for improvedmechanical connection with the block 24 and sidewalls 40LSW 40RSW. Bumps57 will also function to accommodate unavoidable manufacturingvariations in trench width and block dimensions.

The heating element 26 can be made of a thin metal ribbon, foil or wirecloth having a relatively high electrical resistivity. Foil can besolid, or perforated with many small holes. Suitable materials includenickel-chromium alloys, iron-chromium-aluminum (FeCrAl) alloys,stainless steels and the like. The heating element can comprisenickel-chromium or FeCrAl metal foil about 0.001-0.003″ thick, forexample. The electrical resistance of the heating element 26 must bematched to the voltage and current discharge capability of the battery22. For example, the heating element and battery can be matched suchthat the heating element dissipates about 5-40 watts when the device isON.

A portion of the terminal ends 26T of heating element 26 can extendbetween the block 24 and sidewalls 40LSW 40RSW. For example, if theheating element and contacts 50 52 are spot welded, they willnecessarily overlap, and the overlapping portions may be disposedbetween the block and sidewalls.

The heating element 26 illustrated in FIGS. 1, 3 and 4 is corrugated.Corrugation of the heating element is optional in the invention.Corrugation provides a thermally-insulating air gap 45 between theheating element and base 20, thereby minimizing heating of the base 20.

Also, corrugations increase the electrical path length of the heatingelement, which may be necessary to provide an appropriate resistance tomatch a selected battery voltage.

An electronic circuit 55 is disposed in or on the block 24, andconnected to the contacts 50 52 by wires 59. The circuit 55 contains alight emitting diode (LED) or other device or display that indicates tothe user when current is flowing through the heating element 26 (i.e.when voltage is present on the electrical contacts 50 52). The circuit55 can also provide information to the user about the state of charge(i.e. voltage) of the battery 22. For example, the LED can producedifferent colors indicating the different charge states of the battery(e.g. fully charged, partially discharged, and discharged). The circuit55 can be embedded in the block 24 and for example covered with clear ortranslucent potting material, such as silicone rubber.

FIG. 5 shows a cross sectional side view of the window 30, base 20 andslot 34 illustrating how the window 30 and base 20 are attached. Windowmagnet 32 is bonded to the window 30, for example with an adhesive suchas epoxy. Slot 34 contains a base magnet 35. The base magnet is firmlymounted in the slot, for example by press-fit or with adhesive. Thewindow magnet 32 and base magnet 34 are oriented to be magneticallyattracted when the window 30 is disposed on a top surface 20S of thebase 20. Preferably, a slight gap (e.g. 0.005-0.010″) is maintainedbetween the magnets when the window 30 is resting on the top surface20S. This slight gap assures that an attractive force between themagnets pulls the window 30 against the top surface 20S of the base 20.The window can be made of glass, borosilicate glass, or heat-resistantplastics. Preferably, the window 30 is transparent. The magnets can berare-earth magnets (e.g. nickel-plated neodymium-iron-boron magnets).

In an alternative embodiment, the slot 34 and window magnet 32 areshaped (e.g. rectangular, as illustrated in FIG. 1) so that the window30 cannot pivot or rotate around magnets 32 35. Rotation is undesirablein some embodiments because rotation can allow the window to open whenthe vaporizer device is being carried in a clothing pocket, resulting inspilled smoking material. However, a vaporizing device with a rotatingor pivoting window 30 is within the scope of the claimed invention, andis described below.

It is noted that either one of the magnets 32 35 can be replaced with aferromagnetic material, such as steel. In this case, the ferromagneticmaterial is within the scope of the word “magnet” in the appendedclaims.

FIG. 6 shows a cross sectional view illustrating operation of thebattery holder 28. Optional screws 69 attach battery holder 28 to thebase 20. The cantilevered tab 29 presses the battery 22 downward and tothe left in FIG. 6. The battery 22 is thereby pressed against a bottomsurface 40BS of the trench and the left sidewall 40LSW. This pressingforce provides friction, which prevents the battery 22 from falling outof the trench. Also, this pressing force maintains a gap 71; the slidingswitch 39 (not shown) is disposed in the gap 71. The battery holder 28can be made of resilient, strong springy material, such as spring steel,stainless steel, phospor bronze or the like.

In operation, smoking material such as tobacco is disposed in the bowlarea 38. The smoking material should be ground or shredded, and shouldfill only about ¼-½ of the volume of the bowl area 38. Then, the windowcover 30 is placed on the top surface 20S of the base 20. The magnets 3235 hold the window in position over the bowl area 38. The bowl area 38will be almost air tight, but will have enough air leakage to allow auser to inhale from mouthpiece 36.

Next, as illustrated in FIGS. 7A-7B, the battery 22 is inserted into thesecond side 62 of trench 40. For clarity, the battery holder 28 isomitted from FIGS. 7A-7C. It is noted that the battery is stripped ofany plastic or paper coating, so an exterior 64 is bare metal. Theexterior 64 is generally the negative terminal. A button endface 66generally is the positive terminal. Since the heating element 26 is asimple resistive device, polarity is immaterial.

As the battery 22 is inserted, the inner portion 391 rubs and pressesagainst exterior 64, thereby making electrical contact. The innerportion 391 applies a constant pressure against the exterior 64. Thebutton endface positive terminal 66 touches electrical contact 50. Thecontact 50 is cantilevered, and is resilient/springy, so it maintainselectrical contact with positive terminal 66 even if the battery 22moves around slightly.

At this point, with the battery 22 inserted, no electricity flows to theheating element because there is an air gap 68 between the contact 52and the inner portion 391. Compression spring 56 maintains the air gap68 and thereby maintains the device in an OFF condition.

In FIG. 7C, the switch 39 is pressed, thereby moving inner portion 391into contact with electrical contact 52. This completes an electricalcircuit, thereby allowing electrical current from the battery to flowthrough the heating element 26. Compression spring 56 maintains a biasso that electrical current to the heating element is stopped when switch39 is released.

As the heating element 26 becomes hot, it heats the smoking materialdisposed in the bowl area 38. Shaking the device during heating willimprove heat uniformity. A user can observe the heating process throughthe window 30. Visible vapor fog will collect in the bowl area when thesmoking material has been heated to sufficient vaporization temperature.When visible vapor fog is present the user may take a draw from themouthpiece 36.

An advantage of the present design is that the electrical path betweenthe battery 22 and heating element 26 is very short. This minimizesresistive power (I²R) losses. Power efficiency is critical in portablevaporizing devices, and the high current required from a single battery(.e.g. 8-12 amperes) implies that even low electrical resistance willresult in unacceptable power loss. Also, since the electrical contacts50 52 are shaped such that they can be made of a highly conductivematerial such as phosphor bronze, this contributes to the small powerlosses of the present vaporizer device.

FIG. 8 shows an alternative embodiment in which the window is attachedto the base 20 with a rotating/pivoting attachment 72. The rotatingattachment 72 can comprise for example a screw or bolt extending througha hole in the window 30. The screw or bolt can be embedded in or extendthrough the base 20. Rubber or polymeric washers can provide consistentfriction between the window 30 and base 20. Alternatively, rotatingattachment 72 can comprise two cylindrical magnets. One magnet isembedded in and attached to the window 30, and one magnet is disposed inthe base 20. If magnets are used, the window can also be completelyremoved. Embodiments with a rotating/pivoting attachment are within thescope of the appended claims.

FIG. 9 shows a top view of another embodiment in which the slidingswitch 39 is not present. For clarity, the battery holder 28 and window30 are not shown. In FIG. 9, the window 30 and battery holder 28 areomitted for clarity. In the embodiment of FIG. 9, electrical contacts 5052 are resilient and can flex to maintain contact with the battery 22.The embodiment of FIG. 9 is controlled by pressing the battery 22.Pressing the battery as indicated causes the exterior negative terminal64 to touch contact 52, and the button positive terminal 66 to touchcontact 50. Accordingly, power to the heating element 26 is readilycontrolled by pressing battery 22. It is noted that theresilient/springy action of the contacts 50 52 should be designed suchthat a momentary ON switch action is provided. This is easily achievedby making one of the contacts 50 or 52 touch the battery before theother, such that it pushes the battery away (separating the battery fromthe other contact) when the battery is released.

FIG. 10 shows an alternative embodiment in which the battery 22 isrotated 90 degrees. In this embodiment, the inner portion 391 is incontact with the button positive terminal 66. Exterior 64 is touchingcontact 52. Also in this embodiment, the battery holder (not shown forclarity) can also be rotated 90 degrees.

FIG. 11 shows an alternative embodiment in which the trench 40 has acylindrical shape (e.g. is cut with a ball end mill). Closed end 44 offirst side 60 can have a concave spherical shape. Arrow 75 indicates adirection of electrical current flow. Battery holder 28, window 30 andswitch 39 are not shown for clarity. The heating element 26 can beformed, stamped or electroformed, and can be corrugated. FIG. 12 shows atop view of the embodiment of FIG. 11.

FIG. 12 shows a top view of the embodiment of FIG. 11.

FIG. 13 shows an embodiment in which the heating element 26 is orientedhorizontally and is corrugated. The heating element has a gap 80 in themiddle. The heating element 26 of FIG. 13 has a U-shape.

FIG. 14 shows an embodiment in which the electrical contacts 50 52extend through the insulator block 24. This is different from otherembodiments (e.g. FIGS. 1 and 3) in which the contacts 50 52 aredisposed between the block 24 and sidewalls 40RSW 40LSW. The insulatorblock 24 can have through-holes or notches for receiving the electricalcontacts 50 52.

FIG. 15 shows an embodiment in which the heating element 26 has an extrabend 26B. The extra bend means the heating element 26 can be describedas a “w” shape. However, the heating element of FIG. 15 is stillconsidered to have a “U-shape” according to the appended claims, and iswithin the scope of the claimed invention. Also, the heating element 26of FIG. 16 is not corrugated; corrugation of the heating element isoptional in the present invention.

FIG. 16 shows an embodiment in which terminal ends 26T of the heatingelement 26 are closely spaced so that the heating element almost forms aclosed loop. This heating element design is also considered to be“U-shaped” and within the scope of the present invention and appendedclaims. Also, in FIG. 16 the sidewall 40LSW has a wavy “corrugated”shape. This will tend to reducing heat transfer into the base 20.

In FIGS. 9, 10, 11, 12, 13, 14, 15, and 16, the window 30 and batteryholder 28 are not shown for clarity.

FIG. 17 shows an embodiment in which the base 20 has a back wall 84. Thesliding switch 39 extends through a hole in the back wall.

It is noted that the trench can have many shapes. For example, the firstside 60 can have any shape, such as circular, oval, hexagonal or thelike. The first side is not limited to a rectangular shape.

Also, it is noted that the insulator block 24 can be monolithic with thebase 20. For example, the base and block can be molded as a single part,or cut from a single, continuous block of material.

The block can be attached to the base by screws (not illustrated)extending through a bottom of the trench. Alternatively, the block canbe glued to the trench.

Also, it is noted that the battery can be replaced with an electricalconnector in the shape of a battery.

It will be clear to one skilled in the art that the above embodimentsmay be altered in many ways without departing from the scope of theinvention. Accordingly, the scope of the invention should be determinedby the following claims and their legal equivalents.

What is claimed is:
 1. A vaporizing device, comprising: a) a base; b) atrench disposed in the base, comprising a first side and a second side,wherein the first side is for receiving herbal smoking material, and thesecond side is for receiving a battery; c) an insulator block disposedin the trench, between the first side and the second side; d) a U-shapedheating element disposed in the first side, with an open end of theU-shape facing the block; e) two electrical contacts electricallyconnected to terminal ends of the heating element, and extending intothe second side; and f) a cover for covering the first side of thetrench.
 2. The vaporizing device of claim 1 wherein the electricalcontacts extend through the block
 3. The vaporizing device of claim 1wherein the electrical contacts extend between the block and trenchsidewalls.
 4. The vaporizing device of claim 1 wherein the trench isclosed on the first side, and the base comprises a mouthpiece holeextending through the base to the trench first side.
 5. The vaporizingdevice of claim 1 wherein the heating element comprises avertically-oriented strip of metal foil.
 6. The vaporizing device ofclaim 5 wherein the metal foil is corrugated.
 7. The vaporizing deviceof claim 5 wherein the metal foil is perforated.
 8. The vaporizingdevice of claim 1 wherein the heating element comprises avertically-oriented strip of wire cloth.
 9. The vaporizing device ofclaim 1 further comprising a sliding switch movable toward the blocksuch that it can provide a momentary electrical connection between abattery disposed in the second side and one of the electrical contacts.10. The vaporizing device of claim 1 further comprising a battery holderattached to the base and at least partially extending over the secondside, and retaining a battery in the second side by friction.
 11. Thevaporizing device of claim 1 further comprising a base magnet disposedin the base, and a cover magnet attached to the cover, wherein the coveris removably attachable to the base by magnetic attraction between thebase magnet and the cover magnet.
 12. The vaporizing device of claim 11wherein the magnets are shaped such that the cover cannot rotate whenattached to the base.
 13. The vaporizing device of claim 1 furthercomprising a battery charge indicator disposed in or on the insulatorblock.
 14. A vaporizing device, comprising: a) a base comprising atrench; b) an insulator block disposed in the trench, dividing thetrench into a first side and a second side, wherein the second side isdimensioned to receive a battery; c) a U-shaped heating element disposedin the first side, with the open side of the U-shape facing the block;d) two electrical contacts extending between the first side and secondside, wherein the electrical contacts are electrically connected toterminal ends of the heating element; and e) a battery holder extendingover the second side; and f) a cover for covering the first side of thetrench.
 15. The vaporizing device of claim 14 further comprising asliding switch movable toward the block such that it can provide amomentary electrical connection between a battery disposed in the secondside and one of the electrical contacts.
 16. The vaporizing device ofclaim 14 further comprising a base magnet disposed in the base, and acover magnet attached to the cover, wherein the cover is removablyattachable to the base by magnetic attraction between the base magnetand the cover magnet.
 17. The vaporizing device of claim 16 wherein themagnets are shaped such that the cover cannot rotate when attached tothe base.
 18. A vaporizing device, comprising: a) a base comprising atrench; b) an insulator block disposed in the trench, dividing thetrench into a first side and a second side, wherein the second side isdimensioned to receive a battery; c) a U-shaped heating element disposedin the first side, with the open side of the U-shape facing the block;d) two electrical contacts extending between the first side and secondside, wherein the electrical contacts are electrically connected toterminal ends of the heating element; and e) a battery holder extendingover the second side; f) a sliding switch movable toward the block suchthat it can provide a momentary electrical connection between a batterydisposed in the second side and one of the electrical contacts; and g) acover for covering the first side of the trench.
 19. The vaporizingdevice of claim 18 further comprising a base magnet disposed in thebase, and a cover magnet attached to the cover, wherein the cover isremovably attachable to the base by magnetic attraction between the basemagnet and the cover magnet.
 20. The vaporizing device of claim 18further comprising a battery charge indicator electrically connectedbetween the electrical contacts.